Two ideal solutions of A and B are made at one temperature, with $p_A^0=500\mathrm{torr}$ and $p_B^0=100\mathrm{torr}$. Solution 1 has $x_A=0.20$ and solution 2 has $x_A=0.60$. If $2.0\mathrm{mol}$ of solution 1 is mixed with $3.0\mathrm{mol}$ of solution 2, the total vapour pressure of the resulting solution is

1. A$260\mathrm{torr}$
2. B$276\mathrm{torr}$
3. C$244\mathrm{torr}$
4. D$300\mathrm{torr}$